The dome that stands over the baldacchino and the papal altar was designed by Michelangelo, who became chief architect of St. Peter's in 1546. At the time of his death in 1564, the dome was finished as far as the drum, the base on which domes sit. The dome was vaulted between 1585 and 1590 by the architect Giacomo della Porta with the assistance of Domenico Fontana, who was probably the best engineer of the day. Photos don't properly appreciate scale. The Statue of Liberty will fit under this dome.